2-benzyloxy-4-nitro-5-substituted-acylanilide compounds and method of using them

ABSTRACT

Disclosed is a 2-benzyloxy-4-nitro-5-substituted-acylanilide compound of the general formula I:                    
     wherein 
     R is hydrogen or an alkyl group, 
     each R A  is an independently selected substituent and n is 0-5, and 
     Y is a substituent group linked to the rest of the compound by a hetero atom. 
     Also disclosed is a method for using the intermediates in manufacture of dye-forming couplers.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is part of a set of related applications cofiled andcommonly assigned herewith and identified as Attorney Dockets 83445AEK;83536AEK; 83658AEK; 83609AEK; 83681AEK; 83729AEK and 83730AEK, thecontents of which are incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to 2-benzyloxy-4-nitro-5-substituted-acylanilidecompounds and a method of using them.

BACKGROUND OF THE INVENTION

Widely used cyan-dye forming couplers in color photography are4-substituted-2,5-diaminophenol derivatives. Most of these couplers havebeen made from 4-halo-2-aminophenols as basic raw materials. Both aminoand phenol groups are so reactive and sensitive that blocking bothfunctional groups are required prior to introduction or manipulation ofother substituents in the molecule. Formation of oxazole ring is themost commonly used for the blocking purpose. After the blocking, a nitrogroup is introduced at 6-position of benzoxazole (or 5-position ofaminophenol ring) and 5-halo group of benzoxazole (or 4-halo group ofaminophenol) is replaced, if necessary, with other groups bynucleophilic replacement reaction. The benzoxazole ring is then openedby hydrolysis, and a photographically useful group is placed onunblocked amine. Reduction of 5-nitro group gives5-amino-2,4-disubstituted-phenol. Such an aminophenol is difficult tohandle because of its reactivity and sensitivity and it is necessary touse it without isolation in the final step. The final step is usually areaction between 5-amino group and a photographically useful ballastingacyl halide. Such a synthetic route using benzoxazole intermediates hasbeen common and traditional in the synthesis of phenolic cyan couplersand well documented in the literature. Examples are U.S. Pat. No.4,579,813; U.S. Pat. No. 4,743,595; JP60-091355; and M. Ono, et al,Heterocycles (1988), 27(4), 881-4.

Since 2-amino-4-chloro-5-nitrophenol has been commercially available ina bulk quantity, it has been used exclusively as a raw material inmaking 2-equivalent phenolic cyan couplers having a coupling-off groupother than the halogen at 4-position. The phenolic OH group in the rawmaterial is usually blocked by O-benzylation prior to replacement of4-chlorine with other coupling-off group. A photographically usefulfunctional group, typically a urea, is formed on unblocked amine.Reduction of 5-nitro group accomplishes deblocking at the same time togenerate 5-amino-2,4-disubstituted-phenol. It is usually not isolatedand used in the final ballasting reaction. This synthetic sequencestarting from 2-amino-4-chloro-5-nitrophenol has been widely used in thepreparation of 2-equivalent phenolic cyan couplers. Examples are U.S.Pat. No. 4,775,616; 4,849,328; 4,923,791; 5,045,442; and 5,962,198.

A common feature of these two known synthetic routes is to form ‘UreaFirst and Ballast Amide Last’. There are many significant disadvantages,however, in the preparation of 2-eq phenolic cyan couplers in thatmanner.

(1) Benzene ring of benzoxazoles is not activated for nitration so thata harsh reaction condition should be employed. For example, a largeamount of concentrated sulfuric acid and a pre-formed nitronium ionmixture are usually used. Use of such a large amount of concentratedacid as a reaction medium make it difficult to handle during thereaction and to treat waste after the reaction. This is a disadvantagein safety, yield, and cost

(2) Hydrolysis of oxazole ring is difficult. A polar solvent such asN,N-dimethyl formamide, N,N-dimethyl actamide, N-methyl pyrolidone, anddimethyl sulfoxide and a high temperature of over 100° C. are oftenrequired. Use of such a polar solvent is costly and environmentallyunfavorable. Such a high temperature required for hydrolysis ofbenzoxazole containing a nitro group may impose a safety concern. Thisis a disadvantage in environment, safety, yield and cost.

(3) 2-Amino-4-halo-5-nitrophenol is thermally unstable as most of thelow molecular weight aromatic nitro compounds are. Safety is a big issuein using such a thermally unstable compound. There are lots of limitsfor material usage and in reaction condition. This is a disadvantage insafety, yield, and cost.

(4) When 2-amino-4-chloro-5-nitrophenol is blocked by O-benzylation,2-amino group is also benzylated although it is in some small extent.Presence of a small amount of impurity has a big impact on isolation andreduces the yield of product substantially. This is a disadvantage inyield and cost.

(5) Reaction of putting something on the amine at 2-position isdifficult because of deactivation effect of the nitro group present atpara position. It is usually required to employ either an activatedreagent such as a carbamoyl chloride or an isocyanate, or a harshcondition such as a high boiling solvent and a high reactiontemperature. Use of such an activated reagent may be costly andenvironmentally unfavorable. Necessity of employing such a harshcondition for a small molecule containing a nitro group may impose asafety concern. This is another disadvantage in environment, safety,yield and cost.

(6) Something put on the amine may cause other difficulties in thesubsequent reduction step. For instances, if something put on the amineis an urea, its solubility may be limited and a polar solvent such astetrahydrofuran or N,N-dimethylformamide that is costly andenvironmentally unfavorable may be necessary. If a group put on theamine contains a reducible substituent such as halogen, carbonyl, cyano,or nitro group, the subsequent reduction step is complicated andunwanted by-products or impurities may be generated. Generation of suchby-products or impurities in the reduction has a big impact on thesubsequent steps. Particularly, the reduced intermediate, an aminophenolderivative, is too sensitive to handle and it is necessary to be used inthe final step without isolation. The final step of the syntheticsequence is a ballasting step. A ballasted compound is usually difficultto crystallize and purify. Presence of by-products or impurities makesit even worse. Such a difficult and unclean final step reaction hurtsgreatly the yield of final product. A drop in the yield of final stephas a big impact on the cost of manufacturing the coupler. This isanother disadvantage in yield and cost.

(7) All of the difficulties and limitations described above make thecost of manufacturing the coupler so high. It is a major reason why onlya limited number of 2-equivalent phenolic cyan-dye forming couplers havebeen commercialized.

It is therefore desirable to develop a new intermediate and syntheticroute that alleviates all the difficulties and limitations associatedwith the prior arts and helps to reduce the cost of manufacturingphenolic cyan-dye forming couplers.

SUMMARY OF THE INVENTION

The present invention provides a2-benzyloxy-4-nitro-5-substituted-acylanilide compound of the generalformula I:

wherein

R is hydrogen or an alkyl group,

each R^(A) is an independently selected substituent and n is 0-5, and

Y is a substituent group linked to the rest of the compound by a heteroatom.

The compounds of Formula I provide a common intermediate from which avariety of 2-equivalent phenolic cyan-dye forming couplers can beprepared. The intermediates of Formula I can be synthesized in a fewsimple steps from readily available raw materials.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides new intermediates and a synthetic methodinvolving ‘Ballast Amide First and Urea Last’. Advantages of makingcouplers with the new intermediates and the new synthetic method aremultifold.

(1) N-Acyl amine present at 2-position exerts an induction effect toactivate 5-position of the ring. Therefore, nitration can be donecleanly using a dilute nitric acid in environmentally favorable solventsuch as water or acetic acid. This is an advantage in environment,safety, yield, and cost.

(2) Presence of an N-acyl group also assists to reduce thermalinstability of nitro compound prepared, which lessens a risk of unsafehandling and operation in subsequent steps. It is a significantadvantage in the case of that a substituent like a halogen at 4-positionis replaced with other coupling-off group (COG). It can only be doneafter the nitro group is introduced at 5-position. This is anotheradvantage in environment, safety, yield, and cost.

(3) A nitro group is usually reduced by catalytic hydrogenation orhydrogen transfer reduction for economic and environmental reasons. Whenthe nitro group in the intermediates is reduced, the benzyloxy group isalso reduced but N-acyl group is untouched. The aminophenol formed inthis reduction is so clean and has no impurity or byproduct other thanwater and toluene. It therefore can be used without isolation in thenext ballasting step. During these two-step processes, the N-acyl groupunblocked has a significant role. It acts as a buffer to keep such asensitive aminophenol intermediate from being complicated with a sidereaction such as air oxidation or other deterioration. This is anotheradvantage in environment, safety, yield and cost.

(4) The N-acyl group in an intermediate of invention does not affect thesolubility of compound. The intermediates of invention can be used inthe preparation of coupler using a low-cost and environmentallyfavorable solvent. This is another advantage in environment, safety,yield and cost.

(5) The 5-amino group is so reactive that it can be ballasted in thepresence of water or alcohols, at a lower temperature, and in a shortperiod of time. A clean ballasted-amine is obtained in a high yield. Thepresence of an N-acyl group offers yet another advantage. Its presenceassists to make the ballasted compound more crystalline and easilyisolable. This is an advantage in environment, yield and cost.

(6) Deblocking of the N-acyl group can be done typically by base inducedhydrolysis. Obviously, the ballasted amine at 5-position is an N-acylamine similar to the N-acyl at 2-position. However, deacylation of theN-acyl at 2-position can be done selectively without affecting theN-acyl at 5-position. It is because the ballast acyl group at 5-positionis usually a bulky long chain alkyl or a short chain alkyl with a bulkyα-substituent so that its steric bulkiness hinders hydrolytic cleavageof the amide. In addition, a coupling-off group at 4-position providesfurther steric hindrance. This is one of the key unobvious points of thepresent invention and another advantage in environment, safety, yieldand cost.

(7) A deblocked 2-aminophenol derivative that is an immediate precursorof coupler can be obtained cleanly. Although it is still a sensitiveaminophenol, its sensitivity is regulated by the presence of bulkyballast group in the molecule. The 2-amino group is yet so reactive thatthe final ballasting reaction can be done cleanly in a low costenvironmentally favorable solvent at a low temperature and in a shortperiod of time. This is another advantage in environment, yield andcost.

(8) All the advantages of the present invention described abovealleviate almost all of the difficulties and limitations associated withthe prior arts. Using the new intermediates and method of invention,every step of the process of making a coupler can be done safely in anenvironmentally favorable solvent, the minimum labor and burden cost,and the maximum yield and throughput. The present invention heretoforeprovides a method of manufacturing 2-equivalent phenolic cyan-dyeforming couplers in a dramatically reduced cost.

The present invention provides new intermediates,2-benzyloxy-4-nitro-5-substituted-acylanilides, and a novel method forthe preparation of 2-equivalent phenolic cyan-dye forming couplers usingthem.

In the intermediate of Formula I, R is hydrogen, or an unsubstitutedalkyl group, such as alkyl containing 1 to 15, typically 1 to 5 carbonatoms. The R is also a substituted alkyl with a substituent that doesnot adversely affect blocking, deblocking, and other reactions inbetween. The R is a part of N-acyl group that is eventually to beremoved. It is therefore chosen from those that are inexpensive,environmentally favorable, or naturally occurring. Preferred alkyl ismethyl, ethyl, propyl, isopropyl, butyl, pentyl, nonyl, undecyl,tridecyl, pentadecyl, chlorometyl, 1-chloroethyl, 1-chloropropyl,1-chlorobutyl, N-acetylaminomethyl, ethoxycarbonylmethyl,ethoxycarbonylethyl, and the like. Particularly preferred R groups arehydrogen, methyl, ethyl, and propyl. The group defined by Y is a halogenor a substituent group linked to the rest of the compound by a heteroatom (atom other than carbon), and is desirably one of the coupling-offgroups (COGs) known in the photographic art to be replaceable byoxidized color developing agent during photographic processing.Preferred Y groups include aryloxy, arylthio, arylsulfonyl, andheterocyclic. Preferred aryloxy group is phenoxy, 4-chlorophenoxy,4-methylphenoxy, 4-methoxyphenoxy, 4-t-butylphenoxy, 4-t-pentylphenoxy,2,4-di-t-butylphenoxy, or 2,4-di-t-pentyl-phenoxy. Preferred arylthiogroup is phenylthio, 4-methylphenylthio, 4-chloro-phenylthio, or4-methanesulfonylaminophenylthio. Preferred arylsulfonyl group isphenylsulfonyl, p-toluenesulfonyl, 4-chlorophenylsulfonyl, or4-methanesulfonyl-aminophenylsulfonyl. Preferred heterocyclic group is1-imidazolyl, 1-pyrazolyl, 3-N-ethylhydantoin-1-yl,3-N-phenylhydantoin-1-yl, or 5,5-dimethyloxazolidine-2,4-dione-3-yl.R^(A) represents a non-essential substituent which may be any such groupas specified hereinafter such as an alkyl, halogen or carbonamido group.“n” represents the number of such substituents from 0-5 that may bepresent.

The preparation of the new intermediates of invention is shown in SchemeI. The intermediates of Formula I can be made in two ways: (1)O-Benzylation of 2-amino-4-chloro-5-nitrophenol (1), a commerciallyavailable raw material, with benzyl chloride gives a benzyloxyderivative 2. Replacement of chlorine in the compound 2 with an anion ofother coupling-off group (Y⁻) gives a2-benzyloxy-4-nitro-5-substituted-aniline (3). N-acylation of thecompound 3 with an acylating agent defined by general formula RCOZ givesthe desired intermediate of Formula I. The group defined by R is same asdefined above. The group defined by Z is

one commonly known as a leaving group. Preferred Z groups include —OCOR,chloro, phenoxy, methanesulfonyloxy, ethoxycarbonyloxy,phenoxycarbonyloxy, and imidazolyl. (2) Nitration of2-benzyloxy-5-halo-acylanilides whose preparation is described inInvention Disclosure 1 (Docket #83445) gives2-benzyloxy-5-halo-4-nitro-acyanilides (5). Replacement of halogen inthe compound 5 with an anion of the coupling-off group (Y⁻) gives thedesired intermediate of Formula I′ (Formula I′ is Formula I where n=0.)

Scheme II illustrates a new method for the preparation of 2-eq phenoliccyan-dye forming couplers of color photography using the intermediatesof invention. The new method comprises the following steps:

(1) Reduction of nitro group and debenzylation of an intermediate ofFormula I can be done preferably by catalytic hydrogenation or hydrogentransfer reduction. Preferred catalysts are palladium on carbon,platinum on carbon,

Raney nickel, or Raney cobalt. Preferred hydrogen sources are hydrogengas, formic acid, ammonium formate, formate salt of alkali metal such aslithium, sodium, or potassium; hydrazine, or cyclohexene. Reaction iscarried out preferably in an alcoholic solvent such as methanol,ethanol, propanol, or isopropanol; at a lower temperature, typicallyfrom 0° C. to 80° C.; and in a short period of time, typically from 1 to6 hours. The reduction goes smoothly and cleanly producing water andtoluene as only byproducts.

(2) Ballasting reaction is selective acylation on the amine of thecompound 6 using a ballasting agent defined by general formula R′COZ.The group defined by R′ is a part of ballast group that is an organicradical of such size and configuration as to confer on the couplermolecule sufficient bulk to render the coupler substantiallynon-diffusible from the layer in which it is coated in a photographicelement. Representative R′ groups include substituted or unsubstitutedalkyl or aryl groups containing a total of 8-30 carbon atoms.Representative substituents include alkyl, aryl, heteroaryl, alkoxy,aryloxy, alkylthio, arylthio, halogen, alkoxycarbonyl, aryloxycarbonyl,acyl, acyloxy, carbonamido, carbamoyl, alkylsulfonyl, arylsulfonyl,sulfonamido, and sulfamoyl groups where in the alkyl and arylsubstituents, and the alkyl and aryl portions of the alkoxy, aryloxy,alkylthio, arylthio, alkoxycarbonyl, aryloxycarbonyl, acyl, acyloxy,carbonamido, carbamoyl, alkylsulfonyl, arylsulfonyl, sulfonamido, andsulfamoyl substituents contain 1-30 carbon atoms and 6-30 carbon atoms,respectively, and can be further substituted with such substituents.Preferred R′ groups are 1-(2,4-di-t-pentylphenoxy)propyl,1-(2,4-di-t-pentylphenoxy)pentyl, 1-(3-pentadecylphenoxy)propyl,1-dodecylsulfonylpropyl, 1-dodecylsulfonylpentyl,1-dodecylsulfonyl-2-methypropyl, 1- tetradecylsulfonylpropyl,1-hexadecylsulfonylpropyl, 1-(4-butylsulfonylamino-phenoxy)tridecyl,1-(4-dodecyloxy-benzenesulfonyl)propyl, and1-(4-hexadecyloxy-benzenesulfonyl)propyl. The group defined by Z is onecommonly known as a leaving group. Representative Z groups includehalogen, alkoxy, aryloxy, alkylsulfonyloxy, arylsulfonyloxy,alkoxycarbonyloxy, aryloxycarbonyloxy, and heteroaryl. Preferred Zgroups are chloro, phenoxy, methanesulfonyloxy, ethoxycarbonyloxy,phenoxycarbonyloxy, and imidazolyl. Ballasting reaction is preferablydone in a hydrocarbon solvent such as heptane or toluene in the presenceof water or alcohols, at a lower temperature from −10° C. to 40° C. andin a short period of time from 15 minutes to 4 hours. The reactionrequires a weak organic or inorganic base to scavenge the byproduct HZ.Preferred week organic base is pyridine, 4-N,N-dimethylamino-pyridine,2,6-lutidine, or imidazole. Preferred weak inorganic base is sodiumacetate, potassium acetate, ammonium acetate, sodium bicarbonate,potassium bicarbonate, sodium carbonate, potassium carbonate, orammonium carbonate. If the catalytic hydrogen transfer reduction using ahydrogen donor such as ammonium formate or alkali metal formate isemployed for the reduction step, a weak base such as ammonium carbonateor alkali metal carbonate is formed as a byproduct and no additionalbase is necessary at this ballasting step.

(3) Deblocking of 2-N-acyl group of the compound 7 is done by baseinduced hydrolysis. The ballasted amine is so stable that a strong baseand a harsh condition can be employed. The selective hydrolysis can bedone preferably using a strong base such as sodium hydroxide, potassiumhydroxide, or calcium hydroxide; in a high boiling hydrocarbon solventsuch as toluene or xylene with a high boiling alcohol such as butanol orethylene glycol as a co-solvent; at a high temperature from 100° C. to200° C.; and at a short period of time from 1 to 4 hours.

(4) Final step is a selective acylation of the unblocked aminederivative 8 with an acylating agent defined by general formula R″COZ.The group defined by R″ is a photographically useful group that affectsreactivity, sensitivity, and stability of the coupler 9 and hue andother spectral property of the dye formed from the coupler.Representative R″ groups include alkyl, haloalkyl, aryl, heteroaryl,arylamino, and heteroarylamino. Each aryl or heteroaryl portion has nosubstituent or 1 to 5, typically 1 to 2, substituent(s) of the same ordifferent from each other. Representative substituents include, alkyl,aryl, heteroaryl, halogen, cyano, alkoxycarbonyl, aryloxycarbonyl,alkylcarbonyl, arylcarbonyl, heteroaryl-carbonyl, alkylsulfonyl,arylsulfonyl, heteroarysulfonyl, and the like. The group defined by Z isone commonly known as a leaving group. Representative Z groups includehalogen, alkoxy, aryloxy, alkylsulfonyloxy, arylsulfonyloxy,alkoxycarbonyloxy, aryloxycarbonyloxy, and heteroaryl. Preferred Zgroups are chloro, phenoxy, methanesulfonyloxy, ethoxycarbonyloxy,phenoxycarbonyloxy, and imidazolyl. Final acylation is preferably donein an aprotic solvent such as heptane, toluene, ethyl acetate, propylacetate, or acetonitrile at a lower temperature from −10° C. to 40° C.and in a short period of time from 15 minutes to 4 hours. The reactionrequires a weak organic or inorganic base to scavenge the byproduct HZ.Preferred week organic base is pyridine, 4-N,N-dimethylamino-pyridine,2,6-lutidine, or imidazole. Preferred weak inorganic base is sodiumacetate, potassium acetate, ammonium acetate, sodium bicarbonate,potassium bicarbonate, sodium carbonate, potassium carbonate, orammonium carbonate. When R″ is an arylamino or heteroarylamino, anisocyanate of general formula R″NCO may be used instead of R″COZ with nobase.

Unless otherwise specifically stated, use of the term “group”,“substituted” or “substituent” means any group or atom other thanhydrogen. Additionally, when reference is made in this application to acompound or group that contains a substitutable hydrogen, it is alsointended to encompass not only the unsubstituted form, but also its formfurther substituted with any substituent group or groups as hereinmentioned, so long as the substituent does not destroy propertiesnecessary for the intended utility. Suitably, a substituent group may behalogen or may be bonded to the remainder of the molecule by an atom ofcarbon, silicon, oxygen, nitrogen, phosphorous, or sulfur. Thesubstituent may be, for example, halogen, such as chlorine, bromine orfluorine; nitro; hydroxyl; cyano; carboxyl; or groups which may befurther substituted, such as alkyl, including straight or branched chainor cyclic alkyl, such as methyl, trifluoromethyl, ethyl, t-butyl,3-(2,4-di-t-pentylphenoxy) propyl, cyclohexyl, and tetradecyl; alkenyl,such as ethylene, 2-butene; alkoxy, such as methoxy, ethoxy, propoxy,butoxy, 2-methoxyethoxy, sec-butoxy, hexyloxy, 2-ethylhexyloxy,tetradecyloxy, 2-(2,4-di-t-pentylphenoxy)ethoxy, and 2-dodecyloxyethoxy;aryl such as phenyl, 4-t-butylphenyl, 2,4,6-trimethylphenyl, naphthyl;aryloxy, such as phenoxy, 2-methylphenoxy, alpha- or beta-naphthyloxy,and 4-tolyloxy; carbonamido, such as acetamido, benzamido, butyramido,tetradecanamido, alpha-(2,4-di-t-pentyl-phenoxy)acetamido,alpha-(2,4-di-t-pentylphenoxy)butyramido,alpha-(3-pentadecylphenoxy)-hexanamido,alpha-(4-hydroxy-3-t-butylphenoxy)-tetradecanamido,2-oxo-pyrrolidin-1-yl, 2-oxo-5-tetradecylpyrrolin-1-yl,N-methyltetradecanamido, N-succinimido, N-phthalimido,2,5-dioxo-1-oxazolidinyl, 3-dodecyl-2,5-dioxo-1-imidazolyl, andN-acetyl-N-dodecylamino, ethoxycarbonylamino, phenoxycarbonylamino,benzyloxycarbonylamino, hexadecyloxycarbonylamino,2,4-di-t-butylphenoxycarbonylamino, phenylcarbonylamino,2,5-(di-t-pentylphenyl)carbonylamino, p-dodecyl-phenylcarbonylamino,p-tolylcarbonylamino, N-methylureido, N,N-dimethylureido,N-methyl-N-dodecylureido, N-hexadecylureido, N,N-dioctadecylureido,N,N-dioctyl-N′-ethylureido, N-phenylureido, N,N-diphenylureido,N-phenyl-N-p-tolylureido, N-(m-hexadecylphenyl)ureido,N,N-(2,5-di-t-pentylphenyl)-N′-ethylureido, and t-butylcarbonamido;sulfonamido, such as methylsulfonamido, benzenesulfonamido,p-tolylsulfonamido, p-dodecylbenzenesulfonamido,N-methyltetradecylsulfonamido, N,N-dipropyl-sulfamoylamino, andhexadecylsulfonamido; sulfamoyl, such as N-methylsulfamoyl,N-ethylsulfamoyl, N,N-dipropylsulfamoyl, N-hexadecylsulfamoyl,N,N-dimethylsulfamoyl; N-[3-(dodecyloxy)propyl]sulfamoyl,N-[4-(2,4-di-t-pentylphenoxy)butyl]sulfamoyl,N-methyl-N-tetradecylsulfamoyl, and N-dodecylsulfamoyl; carbamoyl, suchas N-methylcarbamoyl, N,N-dibutylcarbamoyl, N-octadecylcarbamoyl,N-[4-(2,4-di-t-pentylphenoxy)butyl]carbamoyl,N-methyl-N-tetradecylcarbamoyl, and N,N-dioctylcarbamoyl; acyl, such asacetyl, (2,4-di-t-amylphenoxy)acetyl, phenoxycarbonyl,p-dodecyloxyphenoxycarbonyl methoxycarbonyl, butoxycarbonyl,tetradecyloxycarbonyl, ethoxycarbonyl, benzyloxycarbonyl,3-pentadecyloxycarbonyl, and dodecyloxycarbonyl; sulfonyl, such asmethoxysulfonyl, octyloxysulfonyl, tetradecyloxysulfonyl,2-ethylhexyloxysulfonyl, phenoxysulfonyl,2,4-di-t-pentylphenoxysulfonyl, methylsulfonyl, octylsulfonyl,2-ethylhexylsulfonyl, dodecylsulfonyl, hexadecylsulfonyl,phenylsulfonyl, 4-nonylphenylsulfonyl, and p-tolylsulfonyl; sulfonyloxy,such as dodecylsulfonyloxy, and hexadecylsulfonyloxy; sulfinyl, such asmethylsulfinyl, octylsulfinyl, 2-ethylhexylsulfinyl, dodecylsulfinyl,hexadecylsulfinyl, phenylsulfinyl, 4-nonylphenylsulfinyl, andp-tolylsulfinyl; thio, such as ethylthio, octylthio, benzylthio,tetradecylthio, 2-(2,4-di-t-pentylphenoxy)ethylthio, phenylthio,2-butoxy-5-t-octylphenylthio, and p-tolylthio; acyloxy, such asacetyloxy, benzoyloxy, octadecanoyloxy, p-dodecylamidobenzoyloxy,N-phenylcarbamoyloxy, N-ethylcarbamoyloxy, and cyclohexylcarbonyloxy;amine, such as phenylanilino, 2-chloroanilino, diethylamine,dodecylamine; imino, such as 1 (N-phenylimido)ethyl, N-succinimido or3-benzylhydantoinyl; phosphate, such as dimethylphosphate andethylbutylphosphate; phosphite, such as diethyl and dihexylphosphite; aheterocyclic group, a heterocyclic oxy group or a heterocyclic thiogroup, each of which may be substituted and which contain a 3 to 7membered heterocyclic ring composed of carbon atoms and at least onehetero atom selected from the group consisting of oxygen, nitrogen andsulfur, such as 2-furyl, 2-thienyl, 2-benzimidazolyloxy or2-benzothiazolyl; quaternary ammonium, such as triethylammonium; andsilyloxy, such as trimethylsilyloxy.

If desired, the substituents may themselves be further substituted oneor more times with the described substituent groups. The particularsubstituents used may be selected by those skilled in the art to attainthe desired photographic properties for a specific application and caninclude, for example, hydrophobic groups, solubilizing groups, blockinggroups, and releasing or releasable groups. When a molecule may have twoor more substituents, the substituents may be joined together to form aring such as a fused ring unless otherwise provided. Generally, theabove groups and substituents thereof may include those having up to 48carbon atoms, typically 1 to 36 carbon atoms and usually less than 24carbon atoms, but greater numbers are possible depending on theparticular substituents selected.

The couplers made with the method of the invention can be used in any ofthe ways and in any of the combinations known in the art. Typically, theinvention materials are incorporated in a melt and coated as a layerdescribed herein on a support to form part of a photographic element.When the term “associated” is employed, it signifies that a reactivecompound is in or adjacent to a specified layer where, duringprocessing, it is capable of reacting with other components.

To control the migration of various components, it may be desirable toinclude a high molecular weight hydrophobe or “ballast” group in couplermolecules. Representative ballast groups include substituted orunsubstituted alkyl or aryl groups containing 8 to 48 carbon atoms.Representative substituents on such groups include alkyl, aryl, alkoxy,aryloxy, alkylthio, hydroxy, halogen, alkoxycarbonyl, aryloxcarbonyl,carboxy, acyl, acyloxy, amino, anilino, carbonamido, carbamoyl,alkylsulfonyl, arylsulfonyl, sulfonamido, and sulfamoyl groups whereinthe substituents typically contain 1 to 42 carbon atoms. Suchsubstituents can also be further substituted.

The photographic elements can be single color elements or multicolorelements. Multicolor elements contain image dye-forming units sensitiveto each of the three primary regions of the spectrum. Each unit cancomprise a single emulsion layer or multiple emulsion layers sensitiveto a given region of the spectrum. The layers of the element, includingthe layers of the image-forming units, can be arranged in various ordersas known in the art. In an alternative format, the emulsions sensitiveto each of the three primary regions of the spectrum can be disposed asa single segmented layer.

A typical multicolor photographic element comprises a support bearing acyan dye image-forming unit comprised of at least one red-sensitivesilver halide emulsion layer having associated therewith at least onecyan dye-forming coupler, a magenta dye image-forming unit comprising atleast one green-sensitive silver halide emulsion layer having associatedtherewith at least one magenta dye-forming coupler, and a yellow dyeimage-forming unit comprising at least one blue-sensitive silver halideemulsion layer having associated therewith at least one yellowdye-forming coupler. The element can contain additional layers, such asfilter layers, interlayers, overcoat layers, and subbing layers.

If desired, the photographic element can be used in conjunction with anapplied magnetic layer as described in Research Disclosure, November1992, Item 34390 published by Kenneth Mason Publications, Ltd., DudleyAnnex, 12a North Street, Emsworth, Hampshire P010 7DQ, ENGLAND, and asdescribed in Hatsumi Kyoukai Koukai Gihou No. 94-6023, published Mar.15, 1994, available from the Japanese Patent Office. When it is desiredto employ the inventive materials in a small format film, ResearchDisclosure, June 1994, Item 36230, provides suitable embodiments.

In the following discussion of suitable materials for use in theemulsions and elements of this invention, reference will be made toResearch Disclosure, September 1996, Item 38957, available as describedabove, which is referred to herein by the term “Research Disclosure”.The Sections hereinafter referred to are Sections of the ResearchDisclosure.

Except as provided, the silver halide emulsion containing elementsemployed in this invention can be either negative-working orpositive-working as indicated by the type of processing instructions(i.e. color negative, reversal, or direct positive processing) providedwith the element. Suitable emulsions and their preparation as well asmethods of chemical and spectral sensitization are described in SectionsI through V. Various additives such as UV dyes, brighteners,antifoggants, stabilizers, light absorbing and scattering materials, andphysical property modifying addenda such as hardeners, coating aids,plasticizers, lubricants and matting agents are described, for example,in Sections II and VI through VIII. Color materials are described inSections X through XIII. Suitable methods for incorporating couplers anddyes, including dispersions in organic solvents, are described inSection X(E). Scan facilitating is described in Section XIV. Supports,exposure, development systems, and processing methods and agents aredescribed in Sections XV to XX. The information contained in theSeptember 1994 Research Disclosure, Item No. 36544 referenced above, isupdated in the September 1996 Research Disclosure, Item No. 38957.Certain desirable photographic elements and processing steps, includingthose useful in conjunction with color reflective prints, are describedin Research Disclosure, Item 37038, February 1995.

Coupling-off groups are well known in the art. Such groups can determinethe chemical equivalency of a coupler, i.e., whether it is a2-equivalent or a 4-equivalent coupler, or modify the reactivity of thecoupler. Such groups can advantageously affect the layer in which thecoupler is coated, or other layers in the photographic recordingmaterial, by performing, after release from the coupler, functions suchas dye formation, dye hue adjustment, development acceleration orinhibition, bleach acceleration or inhibition, electron transferfacilitation, and color correction.

The presence of hydrogen at the coupling site provides a 4-equivalentcoupler, and the presence of another coupling-off group usually providesa 2-equivalent coupler. Representative classes of such coupling-offgroups include, for example, chloro, alkoxy, aryloxy, hetero-oxy,sulfonyloxy, acyloxy, acyl, heterocyclyl, sulfonamido,mercaptotetrazole, benzothiazole, mercaptopropionic acid, phosphonyloxy,arylthio, and arylazo. These coupling-off groups are described in theart, for example, in U.S. Pat. Nos. 2,455,169, 3,227,551, 3,432,521,3,476,563, 3,617,291, 3,880,661, 4,052,212 and 4,134,766; and in UK.Patents and published application U.S. Pat. Nos. 1,466,728, 1,531,927,1,533,039, 2,006,755A and 2,017,704A.

Image dye-forming couplers may be included in the element such ascouplers that form cyan dyes upon reaction with oxidized colordeveloping agents which are described in such representative patents andpublications as: “Farbkuppler-eine Literature Ubersicht,” published inAgfa Mitteilungen, Band III, pp. 156-175 (1961) as well as in U.S. Pat.Nos. 2,367,531; 2,423,730; 2,474,293; 2,772,162; 2,895,826; 3,002,836;3,034,892; 3,041,236; 4,333,999; 4,746,602; 4,753,871; 4,770,988;4,775,616; 4,818,667; 4,818,672; 4,822,729; 4,839,267; 4,840,883;4,849,328; 4,865,961; 4,873,183; 4,883,746; 4,900,656; 4,904,575;4,916,051; 4,921,783; 4,923,791; 4,950,585; 4,971,898; 4,990,436;4,996,139; 5,008,180; 5,015,565; 5,011,765; 5,011,766; 5,017,467;5,045,442; 5,051,347; 5,061,613; 5,071,737; 5,075,207; 5,091,297;5,094,938; 5,104,783; 5,178,993; 5,813,729; 5,187,057; 5,192,651;5,200,305 5,202,224; 5,206,130; 5,208,141; 5,210,011; 5,215,871;5,223,386; 5,227,287; 5,256,526; 5,258,270; 5,272,051; 5,306,610;5,326,682; 5,366,856; 5,378,596; 5,380,638; 5,382,502; 5,384,236;5,397,691; 5,415 990; 5,434,034; 5,441,863; EPO 0 246 616; EPO 0 250201; EPO 0 271 323; EPO 0 295 632; EPO 0 307 927; EPO 0 333 185; EPO 0378 898; EPO 0 389 817; EPO 0 487 111; EPO 0 488 248; EPO 0 539 034; EPO0 545 300; EPO 0 556 700; EPO 0 556 777; EPO 0 556 858; EPO 0 569 979;EPO 0 608 133; EPO 0 636 936; EPO 0 651 286; EPO 0 690 344; German OLS4,026,903; German OLS 3,624,777. and German OLS 3,823,049. Typicallysuch couplers are phenols, naphthols, or pyrazoloazoles.

Couplers that form magenta dyes upon reaction with oxidized colordeveloping agent are described in such representative patents andpublications as: “Farbkuppler-eine Literature Ubersicht,” published inAgfa Mitteilungen, Band III, pp. 126-156 (1961) as well as U.S. Pat.Nos. 2,311,082 and 2,369,489; 2,343,701; 2,600,788; 2,908,573;3,062,653; 3,152,896; 3,519,429; 3,758,309; 3,935,015; 4,540,654;4,745,052; 4,762,775; 4,791,052; 4,812,576; 4,835,094; 4,840,877;4,845,022; 4,853,319; 4,868,099; 4,865,960; 4,871,652; 4,876,182;4,892,805; 4,900,657; 4,910,124; 4,914,013; 4,921,968; 4,929,540;4,933,465; 4,942,116; 4,942,117; 4,942,118; U.S. Pat. No. 4,959,480;4,968,594; 4,988,614; 4,992,361; 5,002,864; 5,021,325; 5,066,575;5,068,171; 5,071,739; 5,100,772; 5,110,942; 5,116,990; 5,118,812;5,134,059; 5,155,016; 5,183,728; 5,234,805; 5,235,058; 5,250,400;5,254,446; 5,262,292; 5,300,407; 5,302,496; 5,336,593; 5,350,667;5,395,968; 5,354,826; 5,358,829; 5,368,998; 5,378,587; 5,409,808;5,411,841; 5,418,123; 5,424,179; EPO 0 257 854; EPO 0 284 240; EPO 0 341204; EPO 347,235; EPO 365,252; EPO 0 422 595; EPO 0 428 899; EPO 0 428902; EPO 0459 331; EPO 0467 327; EPO 0476 949; EPO 0487 081; EPO 0 489333; EPO 0 512 304; EPO 0 515 128; EPO 0 534 703; EPO 0 554 778; EPO 0558 145; EPO 0 571 959; EPO 0 583 832; EPO 0 583 834; EPO 0 584 793; EPO0 602 748; EPO 0 602 749; EPO 0 605 918; EPO 0 622 672; EPO 0 622 673;EPO 0 629 912; EPO 0 646 841, EPO 0 656 561; EPO 0 660 177; EPO 0 686872; WO 90/10253; WO 92/09010; WO 92/10788; WO 92/12464; WO 93/01523; WO93/02392; WO 93/02393; WO 93/07534; UK Application 2,244,053; JapaneseApplication 03192-350; German OLS 3,624,103; German OLS 3,912,265; andGerman OLS 40 08 067. Typically such couplers are pyrazolones,pyrazoloazoles, or pyrazolobenzimidazoles that form magenta dyes uponreaction with oxidized color developing agents.

Couplers that form yellow dyes upon reaction with oxidized colordeveloping agent are described in such representative patents andpublications as: “Farbkuppler-eine Literature Ubersicht,” published inAgfa Mitteilungen; Band III; pp. 112-126 (1961); as well as U.S. Pat.Nos. 2,298,443; 2,407,210; 2,875,057; 3,048,194; 3,265,506; 3,447,928;4,022,620; 4,443,536; 4,758,501; 4,791,050; 4,824,771; 4,824,773;4,855,222; 4,978,605; 4,992,360; 4,994,361; 5,021,333; 5,053,325;5,066,574; 5,066,576; 5,100,773; 5,118,599; 5,143,823; 5,187,055;5,190,848; 5,213,958; 5,215,877; 5,215,878; 5,217,857; 5,219,716;5,238,803; 5,283,166; 5,294,531; 5,306,609; 5,328,818; 5,336,591;5,338,654; 5,358,835; 5,358,838; 5,360,713; 5,362,617; 5,382,506;5,389,504; 5,399,474;. 5,405,737; 5,411,848; 5,427,898; EPO 0 327 976;EPO 0 296 793; EPO 0 365 282; EPO 0 379 309; EPO 0 415 375; EPO 0 437818; EPO 0 447 969; EPO 0 542 463; EPO 0 568 037; EPO 0 568 196; EPO 0568 777; EPO 0 570 006; EPO 0 573 761; EPO 0 608 956; EPO 0 608 957; andEPO 0 628 865. Such couplers are typically open chain ketomethylenecompounds.

Couplers that form colorless products upon reaction with oxidized colordeveloping agent are described in such representative patents as: UK.861,138; U.S. Pat. Nos. 3,632,345; 3,928,041; 3,958,993 and 3,961,959.Typically such couplers are cyclic carbonyl containing compounds thatform colorless products on reaction with an oxidized color developingagent.

Couplers that form black dyes upon reaction with oxidized colordeveloping agent are described in such representative patents as U.S.Pat. Nos. 1,939,231; 2,181,944; 2,333,106; and 4,126,461; German OLS No.2,644,194 and German OLS No. 2,650,764. Typically, such couplers areresorcinols or m-aminophenols that form black or neutral products onreaction with oxidized color developing agent.

In addition to the foregoing, so-called “universal” or “washout”couplers may be employed. These couplers do not contribute to imagedye-formation. Thus, for example, a naphthol having an unsubstitutedcarbamoyl or one substituted with a low molecular weight substituent atthe 2- or 3-position may be employed. Couplers of this type aredescribed, for example, in U.S. Pat. Nos. 5,026,628, 5,151,343, and5,234,800.

It may be useful to use a combination of couplers any of which maycontain known ballasts or coupling-off groups such as those described inU.S. Pat. No. 4,301,235; U.S. Pat. No. 4,853,319 and U.S. Pat. No.4,351,897. The coupler may contain solubilizing groups such as describedin U.S. Pat. 4,482,629. The coupler may also be used in association with“wrong” colored couplers (e.g. to adjust levels of interlayercorrection) and, in color negative applications, with masking couplerssuch as those described in EP 213.490; Japanese Published Application58-172,647; U.S. Pat. Nos. 2,983,608; 4,070,191; and 4,273,861; GermanApplications DE 2,706,117 and DE 2,643,965; UK. Patent 1,530,272; andJapanese Application 58-113935. The masking couplers may be shifted orblocked, if desired.

Typically, couplers are incorporated in a silver halide emulsion layerin a mole ratio to silver of 0.05 to 1.0 and generally 0.1 to 0.5.Usually the couplers are dispersed in a high-boiling organic solvent ina weight ratio of solvent to coupler of 0.1 to 10.0 and typically 0.1 to2.0 although dispersions using no permanent coupler solvent aresometimes employed.

The invention may be used in association with materials that releasePhotographically Useful Groups (PUGS) that accelerate or otherwisemodify the processing steps e.g. of bleaching or fixing to improve thequality of the image. Bleach accelerator releasing couplers such asthose described in EP 193,389; EP 301,477; U.S. Pat. No. 4,163,669; U.S.Pat. No. 4,865,956; and U.S. Pat. No. 4,923,784, may be useful. Alsocontemplated is use in association with nucleating agents, developmentaccelerators or their precursors (UK Patent 2,097,140; UK. Patent2,131,188); electron transfer agents (U.S. Pat. No. 4,859,578; U.S. Pat.No. 4,912,025); antifogging and anti color-mixing agents such asderivatives of hydroquinones, aminophenols, amines, gallic acid;catechol; ascorbic acid; hydrazides; sulfonamidophenols; and noncolor-forming couplers.

The couplers of the invention may further be used in combination withimage-modifying compounds that release PUGS such as “DeveloperInhibitor-Releasing” compounds (DIR's). DIR's useful in conjunction withthe invention are known in the art and examples are described in U.S.Pat. Nos. 3,137,578; 3,148,022; 3,148,062; 3,227,554; 3,384,657;3,379,529; 3,615,506; 3,617,291; 3,620,746; 3,701,783; 3,733,201;4,049,455; 4,095,984; 4,126,459; 4,149,886; 4,150,228; 4,211,562;4,248,962; 4,259,437; 4,362,878; 4,409,323; 4,477,563; 4,782,012;4,962,018; 4,500,634; 4,579,816; 4,607,004; 4,618,571; 4,678,739;4,746,600; 4,746,601; 4,791,049; 4,857,447; 4,865,959; 4,880,342;4,886,736; 4,937,179; 4,946,767; 4,948,716; 4,952,485; 4,956,269;4,959,299; 4,966,835; 4,985,336 as well as in patent publications GB1,560,240; GB 2,007,662; GB 2,032,914; GB 2,099,167; DE 2,842,063, DE2,937,127; DE 3,636,824; DE 3,644,416 as well as the following EuropeanPatent Publications: 272,573; 335,319; 336,411; 346, 899; 362, 870;365,252; 365,346; 373,382; 376,212; 377,463; 378,236; 384,670; 396,486;401,612; 401,613.

Such compounds are also disclosed in “Developer-Inhibitor-Releasing(DIR) Couplers for Color Photography,” C. R. Barr, J. R. Thirtle and P.W. Vittum in Photographic Science and Engineering, Vol. 13, p. 174(1969). Generally, the developer inhibitor-releasing (DIR) couplersinclude a coupler moiety and an inhibitor coupling-off moiety (IN). Theinhibitor-releasing couplers may be of the time-delayed type (DIARcouplers) which also include a timing moiety or chemical switch whichproduces a delayed release of inhibitor. Examples of typical inhibitormoieties are: oxazoles, thiazoles, diazoles, triazoles, oxadiazoles,thiadiazoles, oxathiazoles, thiatriazoles, benzotriazoles, tetrazoles,benzimidazoles, indazoles, isoindazoles, mercaptotetrazoles,selenotetrazoles, mercaptobenzothiazoles, selenobenzothiazoles,mercaptobenzoxazoles, selenobenzoxazoles, mercaptobenzimidazoles,selenobenzimidazoles, benzodiazoles, mercaptooxazoles,mercaptothiadiazoles, mercaptothiazoles, mercaptotriazoles,mercaptooxadiazoles, mercaptodiazoles, mercaptooxathiazoles,telleurotetrazoles or benzisodiazoles. In a preferred embodiment, theinhibitor moiety or group is selected from the following fomulas:

wherein R_(I) is selected from the group consisting of straight andbranched alkyls of from 1 to about 8 carbon atoms, benzyl, phenyl, andalkoxy groups and such groups containing none, one or more than one suchsubstituent; R_(II) is selected from R_(I) and —SR_(I); R_(III) is astraight or branched alkyl group of from 1 to about 5 carbon atoms and mis from 1 to 3; and R_(IV) is selected from the group consisting ofhydrogen, halogens and alkoxy, phenyl and carbonamido groups, —COOR_(V)and —NHCOOR_(V) wherein R_(V) is selected from substituted andunsubstituted alkyl and aryl groups.

Although it is typical that the coupler moiety included in the developerinhibitor-releasing coupler forms an image dye corresponding to thelayer in which it is located, it may also form a different color as oneassociated with a different film layer. It may also be useful that thecoupler moiety included in the developer inhibitor-releasing couplerforms colorless products and/or products that wash out of thephotographic material during processing (so-called “universal”couplers).

A compound such as a coupler may release a PUG directly upon reaction ofthe compound during processing, or indirectly through a timing orlinking group. A timing group produces the time-delayed release of thePUG such groups using an intramolecular nucleophilic substitutionreaction (U.S. Pat. No. 4,248,962); groups utilizing an electrontransfer reaction along a conjugated system (U.S. Pat. No. 4,409,323;4,421,845; 4,861,701, Japanese Applications 57-188035; 58-98728;58-209736; 58-209738); groups that function as a coupler or reducingagent after the coupler reaction (U.S. Pat. No. 4,438,193; U.S. Pat. No.4,618,571) and groups that combine the features describe above. It istypical that the timing group is of one of the formulas:

wherein IN is the inhibitor moiety, R_(VII) is selected from the groupconsisting of nitro, cyano, alkylsulfonyl; sulfamoyl; and sulfonamidogroups; a is 0 or 1; and R_(VI) is selected from the group consisting ofsubstituted and unsubstituted alkyl and phenyl groups. The oxygen atomof each timing group is bonded to the coupling-off position of therespective coupler moiety of the DIAR.

The timing or linking groups may also function by electron transfer downan unconjugated chain. Linking groups are known in the art under variousnames. Often they have been referred to as groups capable of utilizing ahemiacetal or iminoketal cleavage reaction or as groups capable ofutilizing a cleavage reaction due to ester hydrolysis such as U.S. Pat.No. 4,546,073. This electron transfer down an unconjugated chaintypically results in a relatively fast decomposition and the productionof carbon dioxide, formaldehyde, or other low molecular weightby-products. The groups are exemplified in EP 464,612, EP 523,451, U.S.Pat. No. 4,146,396, Japanese Kokai 60-249148 and 60-249149.

Suitable developer inhibitor-releasing couplers for use in the presentinvention include, but are not limited to, the following:

It is also contemplated that the present invention may be employed toobtain reflection color prints as described in Research Disclosure,November 1979, Item 18716, available from Kenneth Mason Publications,Ltd, Dudley Annex, 12a North Street, Emsworth, Hampshire P0101 7DQ,England. Materials useful in the invention may be coated on pH adjustedsupport as described in U.S. Pat. No. 4,917,994; on a support withreduced oxygen permeability (EP 553,339); with epoxy solvents (EP164,961); with nickel complex stabilizers (U.S. Pat. No. 4,346,165; U.S.Pat. No. 4,540,653 and U.S. Pat. No. 4,906,559 for example); withballasted chelating agents such as those in U.S. Pat. No. 4,994,359 toreduce sensitivity to polyvalent cations such as calcium; and with stainreducing compounds such as described in U.S. Pat. No. 5,068,171. Othercompounds useful in combination with the invention are disclosed inJapanese Published Applications described in Derwent Abstracts havingaccession numbers as follows: 90-072,629, 90-072,630; 90-072,631;90-072,632; 90-072,633; 90-072,634; 90-077,822; 90-078,229; 90-078,230;90-079,336; 90-079,337; 90-079,338; 90-079,690; 90-079,691; 90-080,487;90-080,488; 90-080,489; 90-080,490; 90-080,491; 90-080,492; 90-080,494;90-085,928; 90-086,669; 90-086,670; 90-087,360; 90-087,361; 90-087,362;90-087,363; 90-087,364; 90-088,097; 90-093,662; 90-093,663; 90-093,664;90-093,665; 90-093,666; 90-093,668; 90-094,055; 90-094,056; 90-103,409;83-62,586; 83-09,959.

Conventional radiation-sensitive silver halide emulsions can be employedin the practice of this invention. Such emulsions are illustrated byResearch Disclosure, Item 38755, September 1996, I. Emulsion grains andtheir preparation.

Useful in this invention are tabular grain silver halide emulsions.Tabular grains are those having two parallel major crystal faces andhaving an aspect ratio of at least 2. The term “aspect ratio” is theratio of the equivalent circular diameter (ECD) of a grain major facedivided by its thickness (t). Tabular grain emulsions are those in whichthe tabular grains account for at least 50 percent (preferably at least70 percent and optimally at least 90 percent) of the total grainprojected area. Preferred tabular grain emulsions are those in which theaverage thickness of the tabular grains is less than 0.3 micrometer(preferably thin—that is, less than 0.2 micrometer and most preferablyultrathin—that is, less than 0.07 micrometer). The major faces of thetabular grains can lie in either {111 } or {100} crystal planes. Themean ECD of tabular grain emulsions rarely exceeds 10 micrometers andmore typically is less than 5 micrometers.

In their most widely used form tabular grain emulsions are high bromide{111} tabular grain emulsions. Such emulsions are illustrated by Kofronet al U.S. Pat. No. 4,439,520, Wilgus et al U.S. Pat. No. 4,434,226,Solberg et al U.S. Pat. No. 4,433,048, Maskasky U.S. Pat. Nos.4,435,501, 4,463,087 and 4,173,320, Daubendiek et al U.S. Pat. Nos.4,414,310 and 4,914,014, Sowinski et al U.S. Pat. No. 4,656,122, Pigginet al U.S. Pat. Nos. 5,061,616 and 5,061,609, Tsaur et al U.S. Pat. Nos.5,147,771, '772, '773, 5,171,659 and 5,252,453, Black et al 5,219,720and 5,334,495, Delton U.S. Pat. Nos. 5,310,644, 5,372,927 and 5,460,934,Wen U.S. Pat. No. 5,470,698, Fenton et al U.S. Pat. No. 5,476,760,Eshelman et al U.S. Pat. Nos. 5,612,,175 and 5,614,359, and Irving et alU.S. Pat. No. 5,667,954.

Ultrathin high bromide {111 } tabular grain emulsions are illustrated byDaubendiek et al U.S. Pat. Nos. 4,672,027, 4,693,964, 5,494,789,5,503,971 and 5,576,168, Antoniades et al U.S. Pat. No. 5,250,403, Olmet al U.S. Pat. No. 5,503,970, Deaton et al U.S. Pat. No. 5,582,965, andMaskasky U.S. Pat. No. 5,667,955.

High bromide {100} tabular grain emulsions are illustrated by MignotU.S. Pat. Nos. 4,386,156 and 5,386,156.

High chloride {111 } tabular grain emulsions are illustrated by Wey U.S.Pat. No. 4,399,215, Wey et al U.S. Pat. No. 4,414,306, Maskasky U.S.Pat. Nos. 4,400,463, 4,713,323, 5,061,617, 5,178,997, 5,183,732,5,185,239, 5,399,478 and 5,411,852, and Maskasky et al U.S. Pat. Nos.5,176,992 and 5,178,998. Ultrathin high chloride {111} tabular grainemulsions are illustrated by Maskasky U.S. Pat. Nos. 5,271,858 and5,389,509.

High chloride {100} tabular grain emulsions are illustrated by MaskaskyU.S. Pat. Nos. 5,264,337, 5,292,632, 5,275,930 and 5,399,477, House etal U.S. Pat. No. 5,320,938, Brust et al U.S. Pat. No. 5,314,798,Szajewski et al U.S. Pat. No. 5,356,764, Chang et al U.S. Pat. Nos.5,413,904 and 5,663,041, Oyamada U.S. Pat. No. 5,593,821, Yamashita etal U.S. Pat. Nos. 5,641,620 and 5,652,088, Saitou et al U.S. Pat. No.5,652,089, and Oyamada et al U.S. Pat. No. 5,665,530.

Ultrathin high chloride {100} tabular grain emulsions can be prepared bynucleation in the presence of iodide, following the teaching of House etal and Chang et al, cited above.

The emulsions can be surface-sensitive emulsions, i.e., emulsions thatform latent images primarily on the surfaces of the silver halidegrains, or the emulsions can form internal latent images predominantlyin the interior of the silver halide grains. The emulsions can benegative-working emulsions, such as surface-sensitive emulsions orunfogged internal latent image-forming emulsions, or direct-positiveemulsions of the unfogged, internal latent image-forming type, which arepositive-working when development is conducted with uniform lightexposure or in the presence of a nucleating agent. Tabular grainemulsions of the latter type are illustrated by Evans et al. U.S. Pat.No. 4,504,570.

Photographic elements can be exposed to actinic radiation, typically inthe visible region of the spectrum, to form a latent image and can thenbe processed to form a visible dye image. Processing to form a visibledye image includes the step of contacting the element with acolor-developing agent to reduce developable silver halide and oxidizethe color-developing agent. Oxidized color developing agent in turnreacts with the coupler to yield a dye. If desired “Redox Amplification”as described in Research Disclosure XVIIIB(5) may be used.

A “color negative element” utilizes negative-working silver halide andprovides a negative image upon processing. A first type of such elementis a capture element, which is a color negative film that is designedfor capturing an image in negative form rather than for viewing animage. A second type of such an element is a direct-view element that isdesigned, at least in part, for providing a positive image viewable byhumans.

In the capture element, speed (the sensitivity of the element to lowlight conditions) is usually critical to obtaining sufficient image insuch elements. Such elements are typically silver bromoiodide emulsionscoated on a transparent support and are sold packaged with instructionsto process in known color negative processes such as the Kodak C-41process as described in The British Journal of Photography Annual of1988, pages 191-198. If a color negative film element is to besubsequently employed to generate a viewable projection print as for amotion picture, a process such as the Kodak ECN-2 process described inthe H-24 Manual available from Eastman Kodak Co. may be employed toprovide the color negative image on a transparent support. Colornegative development times are typically 3′15″ or less and desirably 90or even 60 seconds or less.

A direct-view photographic element is one which yields a color imagethat is designed for human viewing (1) by reflected light, such as aphotographic paper print, (2) by transmitted light, such as a displaytransparency, or (3) by projection, such as a color slide or a motionpicture print. These directview elements may be exposed and processed ina variety of ways. For example, paper prints, display transparencies,and motion picture prints are typically produced by digitally printingor by optically printing an image from a color negative onto thedirect-viewing element and processing though an appropriatenegative-working photographic process to give a positive color image.The element may be sold packaged with instructions for digital printingor for processing using a color negative optical printing process, forexample the Kodak RA-4 process, as generally described in PCT WO87/04534 or U.S. Pat. No. 4,975,357, to form a positive image. Colorprojection prints may be processed, for example, in accordance with theKodak ECP-2 process as described in the H-24 Manual. Color printdevelopment times are typically 90 seconds or less and desirably 45 oreven 30 seconds or less. Color slides may be produced in a similarmanner but are more typically produced by exposing the film directly ina camera and processing through a reversal color process or a directpositive process to give a positive color image. The foregoing imagesmay also be produced by alternative processes such as digital printing.

Each of these types of photographic elements has its own particularrequirements for dye hue, but in general they all require cyan dyeswhose absorption bands are less deeply absorbing (that is, shifted awayfrom the red end of the spectrum) than color negative films. This isbecause dyes in direct-view elements are selected to have the bestappearance when viewed by human eyes, whereas the dyes in image capturematerials are designed to best match the needs of the printing process.

A reversal element is capable of forming a positive image withoutoptical printing. To provide a positive (or reversal) image, the colordevelopment step is preceded by development with a non-chromogenicdeveloping agent to develop exposed silver halide, but not form dye, andfollowed by uniformly fogging the element to render unexposed silverhalide developable. Such reversal elements are typically sold packagedwith instructions to process using a color reversal process such as theKodak E-6 process as described in The British Journal of PhotographyAnnual of 1988, page 194. Alternatively, a direct positive emulsion canbe employed to obtain a positive image.

The above elements are typically sold with instructions to process usingthe appropriate method such as the mentioned color negative (KodakC-41), color print (Kodak RA-4), or reversal (Kodak E-6) process.

The photographic element of the invention can be incorporated intoexposure structures intended for repeated use or exposure structuresintended for limited use, variously referred to by names such as “singleuse cameras”, “lens with film”, or “photosensitive material packageunits”.

Preferred color developing agents are p-phenylenediamines such as:

4-amino-N,N-diethylaniline hydrochloride,

4-amino-3-methyl-N,N-diethylaniline hydrochloride,

4-amino-3-methyl-N-ethyl-N-(2-methanesulfonamidoethyl)anilinesesquisulfate hydrate,

4-amino-3-methyl-N-ethyl-N-(2-hydroxyethyl)aniline sulfate,

4-amino-3 -(2-methanesulfonamidoethyl)-N,N-diethylaniline hydrochloride,and

4-amino-N-ethyl-N-(2-methoxyethyl)-m-toluidine di-p-toluene sulfonicacid.

Development is usually followed by the conventional steps of bleaching,fixing, or bleach-fixing, to remove silver or silver halide, washing,and drying.

EXAMPLES

In the following are described the preparation of two new intermediatesof invention (Examples 1 and 2) and their uses in the preparation of2-eq phenolic cyan-dye forming couplers (Examples 3 and 4).

Example 1 2-Benzyloxy-5-(4-methoxyphenoxy)-4-nitro-acetanilide (FormulaI; R=CH₃ and Y=4-Methoxyphenoxy)

In a 500-ml flask, place 18.9 g (0.1 m) of2-amino-4-chloro-5-nitrophenol (1) and 120 ml of acetone, and heat to50° C. Add 7.2 g (0.1 m×1.15@90%) of KOH flakes and stir at 55° C. tomake a deep red brown solution. Add 6.9 g (0.05 m) of potassiumcarbonate, 0.8 g of tetrabutyl ammonium bromide and 14.6 g (0.1 m×1.15)of benzyl chloride. Stir the reaction mixture under reflux with faststirring for 3 hrs. Cool the mixture to room temperature and add 240 mlof water slowly. Stir the resulting slurry and cool to 20° C. Collectsolid, wash with water and heptane, and dry in an air oven to give 25.4g (91%) of 2-benzyloxy-5-chloro-4-nitroaniline (2) as yellow granularsolids.

In a 500-ml flask, place 24.2 g (0.15 m×1.3) of 4-methoxyphenol, 250 mlof toluene, 15 ml of N,N-dimethylacetamide, and 11.22 g (0.15 m×1.2@90%)of KOH flakes. Heat the mixture under reflux with Dean-Stark trap tocollect approximately 5 ml of water and 20 ml of toluene over 1 hr. Coolwhite slurry mixture to 90° C., and add 41.8 g (0.15 m) of2-benzyloxy-5-chloro-4-nitroaniline (2) and 1 g of tetrabutylammoniumbromide. Heat under reflux for 1 hr. Addition of 1 g of phase transferagent, tetrabutylammonium bromide, and heat under reflux for 1 hr periodis repeated 3 more times. At the end of the 4 hrs reflux period,concentrate the reaction mixture by distilling off about 100 ml oftoluene and cool the mixture containing2-benzyloxy-5-(4-methoxyphenoxy)-4-nitro-aniline (3a;Y=4-methoxyphenoxy) to 70° C. Add 0.6 g of pyridine and 23.0 g (0.15m×1.5) of acetic anhydride. Heat the reaction mixture under reflux for 1hr, and add 120 ml of 5% HCl solution and stir for 15 min at 70° C.Separate toluene solution, wash with 120 ml of 5% HCl solution, andconcentrate under a reduced pressure to a thick oil. Add 200 ml ofheptane and stir vigorously at room temperature for 4 hrs and cool to10° C. in an ice-water bath. Collect solid, wash with heptane, dry inair to give 55.2 g (90%) of2-benzyloxy-5-(4-methoxyphenoxy)-4-nitro-acetanilide (Formula I; R=CH₃and Y=4-methoxyphenoxy) as yellow solids.

Example 2 2-Benzyloxy-5-(4-t-pentylphenoxy)-4-nitro-acetanilide (FormulaI; R=CH₃ and Y=4-t-Pentylphenoxy)

In a 500-ml flask, place 32.0 g (0.15 m×1.3) of 4-t-pentylphenol, 250 mlof toluene, 15 ml of N,N-dimethylacetamide, and 1 1.22 g (0.15m×1.2@90%) of KOH flakes. Heat the mixture under reflux with Dean-Starktrap to collect approximately 5 ml of water and 20 ml of toluene over 1hr. Cool white slurry mixture to 90° C., and add 41.8 g (0.15 m) of2-benzyloxy-5-chloro-4-nitroaniline (2) and 1 g of tetrabutylammoniumbromide. Heat under reflux for 1 hr. Addition of 1 g of phase transferagent, tetrabutylammonium bromide, and heat under reflux for 1 hr periodis repeated 3 more times. At the end of the 4 hrs reflux period, coolthe reaction mixture to 90° C., add 100 ml of hot water and stir for afew min. Separate toluene solution, wash with 100 ml of hot water,concentrate the reaction mixture by distilling off toluene under areduced pressure at a pot temperature of 60° C. Add 200 ml of heptaneslowly at 60° C., cool to room temperature, and let it stand over night.Collect solid, wash with 10% toluene in heptane, dry in air to give 55.5g (91%) of 2-benzyloxy-5-(4-t-pentylphenoxy)-4-nitro-aniline (3b;Y=4-t-pentylphenoxy).

In a 500-ml flask, place 44.7 g (0.11 m) of2-benzyloxy-5-(4-t-pentyl-phenoxy)-4-nitro-aniline (3b), 220 ml oftoluene, and 16.8 g (0.11 m×1.5) of acetic anhydride. Heat the reactionmixture with fast stirring on a steam bath for 2 hrs. Cool to 65° C.,and add 120 ml of 1N HCl and stir at 60°-65° C. for 10 min. Separatetoluene, wash with 100 ml of warm (60° C.) water, and concentrate undera reduced pressure to a thick oil. Add 250 ml of heptane slowly withfast stirring and let the resulting dull yellow solid mass stand at roomtemperature for 1 hr. Collect solid, wash with 10% toluene in heptane,and dry in air to give 46.3 g (94%) of2-benzyloxy-5-(4-t-pentylphenoxy)-4-nitro-acetanilide (Formula I; R=CH3and Y=4-t-pentylphenoxy) as yellow solids.

Example 3 A 2-eq Phenolic Cyan Coupler 9a(R′=1-(2,4-di-t-Pentylphenoxy-pentyl, R″=4-cyanopheylamino, andY=4-Methoxyphenoxy) from2-Benzyloxy-5-(4-methoxyphenoxy)-4-nitro-acetanilide (Formula I; R=CH₃and Y=4-Methoxyphenoxy)

In a 500-ml flask, place 20.4 g (0.05 m) of2-benzyloxy-5-(4-methoxy-phenoxy)-4-nitro-acetanilide (Formula I; R=CH₃and Y=4-methoxyphenoxy), 80 ml of isopropyl alcohol and 40 ml oftoluene. Heat the mixture to 60° C. Add 1.0 g of 5% Pd/C wet with 1 mlof water and 21.0 g (0.25 m) of potassium formate in 40 ml of water.Stir the reaction mixture vigorously at 60°-65° C. for 3 hrs undernitrogen. Cool the reaction mixture containing4-amino-2-hydroxy-5-(4-methoxyphenoxy)acetanilide (6a; R=CH₃ andY=4-methoxyphenoxy) to 15° C. and add 19.8 g (0.05 m×1.03@95%) of2-(2,4-di-t-pentylphenoxy)hexanoyl chloride (R′COZ;R′=1-(2,4-di-t-pentylphenoxy)pentyl and Z=Cl) in 60 ml of toluene slowlyin drop wise over 1 hr period. Stir the mixture at 15° C. for another 30min. Filter off catalyst and wash with a small volume of toluene andwater. Separate toluene solution, wash with 100 ml of 1N HCl twice, andconcentrate under a reduced pressure to a thick oil. Add 160 ml ofheptane to the oil with gentle stirring. Let it stand at roomtemperature for 1 hr. Collect solid, wash with heptane, and dry in avacuum oven to give 28.2 g (91%) of4-{2-(2,4-di-t-pentylphenoxy)hexanoyl}amino-2-hydroxy-5-(4-methoxyphenoxy)-acetanilide(7a; R=CH₃, R′=1-(2,4-di-t-pentylphenoxy)pentyl, andY=4-methoxy-phenoxy).

In a 500-ml flask inert with nitrogen, place 22.3 g (0.036 m) of4-{2-(2,4-di-t-pentylphenoxy)hexanoyl}amino-2-hydroxy-5-(4-methoxyphenoxy)acetanilide(7a), 120 ml of xylene, 12 ml of ethylene glycol, and 8.0 g of calciumhydroxide. Heat under reflux collecting approximately 7 ml ofwater-ethylene glycol and 20 ml of xylene in a Dean-Stark trap. Detachthe trap and heat under reflux for 5 hrs. Cool to 80° C. and add 100 mlof toluene, 100 ml of hot water, 25 ml of acetic acid, and 2 g sodiumhydrosulfite. Stir the mixture at 60°-65° C. for 15 min and filterthrough a Celite pad to remove interlayer insolubles. Separatetoluene-xylene solution, wash with 100 ml of hot water, and concentrateunder a reduced pressure to a thick oil. Dissolve the oil in 200 ml ofheptane and stand at room temperature over night. Collect solid, washwith heptane, and dry in a vacuum oven to give 19.5 g (94%) of2-amino-5-{2-(2,4-di-t-pentylphenoxy)hexanoyl}amino-4-(4-methoxyphenoxy)phenol(8a; R′=1-(2,4-di-t-pentylphenoxy)pentyl and Y=4-methoxyphenoxy).

In a 250-ml flask inert with nitrogen, place 14.4 g (0.025 m) of2-amino-5-{2-(2,4-di-t-pentylphenoxy)hexanoyl}amino-4-(4-methoxyphenoxy)phenol(8a), 6.0 g (0.025 m) of phenyl 4-cyanophenylaminocarbarmate (R″COZ;R″=4-cyanophenylamino and Z=phenoxy), 1.7 g (0.025 m) of imidazole, and75 ml of ethyl acetate. Heat the mixture under reflux for 4.5 hrs. Add75 ml of hot water and 50 ml of 1N HCl and stir for a few min. Separateethyl acetate solution, wash with 100 ml of warm water, and concentrateto a thick oil. Dissolve the oil in 40 ml of acetonitrile and let itstand at room temperature over night. Collect solid, wash withacetonitrile and dry in a vacuum oven to give 15.3 g (85%) of thecoupler 9a (R′=1-(2,4-di-t-pentylphenoxy)pentyl, R″=4-cyanophenylamino,and Y=4-methoxyphenoxy) as white solids.

Example 4 A 2-eq Phenolic Cyan Coupler 9b(R′=1-(2,4-di-t-Pentylphenoxy)-pentyl, R″=4-Cyanophenylamino, andY=4-t-Pentylphenoxy) from2-Benzyloxy-5-(4-t-pentylphenoxy)-4-nitro-acetanilide (Formula I; R=CH₃and Y=4-t-Pentylphenoxy)

In a 500-ml flask, place 22.4 g (0.05 m) of2-benzyloxy-5-(4-t-pentyl-phenoxy)-4-nitro-acetanilide (Formula I; R=CH₃and Y=4-t-pentylphenoxy), 80 ml of isopropyl alcohol and 40 ml oftoluene. Heat the mixture to 60° C. Add 1.0 g of 5% Pd/C wet with 1 mlof water and 21.0 g (0.25 m) of potassium formate in 40 ml of water.Stir the reaction mixture vigorously at 60°-70° C. for 3 hrs undernitrogen. Cool the reaction mixture containing4-amino-2-hydroxy-5-(4-t-pentylphenoxy)-acetanilide (6b; R=CH₃ andY=4-t-pentylphenoxy) to 15° C. and add 20.3 g (0.05 m×1.05@95%) of2-(2,4-di-t-pentylphenoxy)hexanoyl chloride (R′COZ;R′=1-(2,4-di-t-pentylphenoxy)pentyl and Z=Cl) in 80 ml of toluene slowlyin drop wise over 1 hr period. Stir the mixture at 15° C. for another 30min. Filter off catalyst and wash with a small volume of toluene andwater. Separate toluene solution, wash with 100 ml of 1N HCl twice, andconcentrate under a reduced pressure to a thick oil. Add 225 ml ofheptane to the oil with gentle stirring. Cool in an ice-water bath for 1hr. Collect solid, wash with heptane, and dry in a vacuum oven to give30.0 g (91%) of4-{2-(2,4-di-t-pentylphenoxy)hexanoyl}amino-2-hydroxy-5-(4-t-pentylphenoxy)-acetanilide(7b; R=CH₃, R′=1-(2,4-di-t-pentylphenoxy)pentyl, andY=4-t-pentylphenoxy).

In a 500-ml flask inert with nitrogen, place 23.7 g (0.036 m) of4-{2-(2,4-di-t-pentylphenoxy)hexanoyl}amino-2-hydroxy-5-(4-t-pentylphenoxy)-acetanilide(7b) 120 ml of xylene, 12 ml of ethylene glycol, and 8.0 g of calciumhydroxide. Heat under reflux collecting approximately 7 ml ofwater-ethylene glycol and 20 ml of xylene in a Dean-Stark trap. Detachthe trap and heat under reflux for 5 hrs. Cool to 80° C. and add 100 mlof toluene, 100 ml of hot water, 25 ml of acetic acid, and 2 g sodiumhydrosulfite. Stir the mixture at 60°-65° C. for 15 min and filterthrough a Celite pad to remove interlayer insolubles. Separatetoluene-xylene solution, wash with 100 ml of hot water+12 ml of aceticacid+2 g sodium hydrosulfite and 100 ml of hot water twice, andconcentrate under a reduced pressure to a thick oil. Dissolve the oil in200 ml of heptane, add a seed crystals, and stand at room temperatureover night. Cool in an ice-water bath for 1 hr, collect solid, wash withheptane, and dry in a vacuum oven to give 20.4 g (92%) of2-amino-5-{2-(2,4-di-t-pentylphenoxy)hexanoyl}amino-4-(4-t-pentylphenoxy)-phenol(8b; R′=1-(2,4-di-t-pentylphenoxy)pentyl and Y=4-methoxyphenoxy).

In a 250-ml flask inert with nitrogen, place 15.4 g (0.025 m) of2-amino-5-{2-(2,4-di-t-pentylphenoxy)hexanoyl}amino-4-(4-t-pentylphenoxy)-phenol(8b), 6.0 g (0.025 m) of phenyl 4-cyanophenylaminocarbarmate (R″COZ;R″=4-cyanophenylamino and Z=phenoxy), 1.7 g (0.025 m) of imidazole, and75 ml of ethyl acetate. Heat the mixture under reflux for 5 hrs. Add 75ml of hot water and 50 ml of 1N HCl and stir for a few min. Separateethyl acetate solution, wash with 100 ml of warm water, and concentrateto a thick oil. Dissolve the oil in 50 ml of toluene, add 100 ml ofheptane and seed crystals, and let it stand at room temperature overnight. Cool in an ice-water bath for 1 hr, collect solid, wash withheptane and dry in a vacuum oven to give 16.2 g (85%) of the coupler 9b(R′=1-(2,4-di-t-pentylphenoxy)pentyl, R″=4-cyanophenylamino, andY=4-t-pentyl-phenoxy) as white solids.

The invention has been described in detail with particular reference tocertain preferred embodiments thereof, but it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention.

The entire contents of the patents and other publications referred to inthis specification are incorporated herein by reference.

What is claimed is:
 1. A 2-benzyloxy-4-nitro-5-substituted-acylanilidecompound of the general formula I:

wherein R is hydrogen or an alkyl group containing 1-15 carbon atoms,and Y is a substituent group linked to the rest of the compound by ahetero atom, the group being selected from phenoxy, 4chlorophenoxy,4-methylphenoxy, 4-methoxyphenoxy, 4-t-butylphenoxy, 4-t-pentylphenoxy,2,4-di-t-butyl-phenoxy, 2,4-di-t-pentyl-phenoxy, an arylthio, anarylsulfonyl, and a heterocyclic group.
 2. The compound of claim 1wherein R is a methyl, ethyl, propyl, isopropyl, butyl, pentyl, nonyl,undecyl, tridecyl, pentadecyl, chlorometyl, 1-chloroethyl,1-chloropropyl, 1-chlorobutyl, N-acetylaminomethyl,ethoxycarbonylmethyl, or ethoxycarbonylethyl group.
 3. The compound ofclaim 1 where in Y is an arylthio, arylsulfonyl, or a heterocyclicgroup.
 4. The compound of claim 1 wherein Y is a phenoxy,4-chlorophenoxy, 4-methylphenoxy, 4-methoxyphenoxy, 4-t-butylphenoxy,4-t-pentylphenoxy, 2,4-di-t-butylphenoxy, or 2,4-di-t-pentyl-phenoxygroup.
 5. The compound of claim 3 wherein Y is a 4-methyl-phenylthio,4-chloro-phenylthio, or 4-methanesulfonylaminophenylthio group.
 6. Thecompound of claim 3 wherein Y is an arylsulfonyl group and is aphenylsulfonyl, p-toluenesulfonyl, 4-chlorophenylsulfonyl, or4-methanesulfonylaminophenylsulfonyl group.
 7. The compound of claim 3wherein Y is a heterocyclic group and is a 1-imidazolyl, 1-pyrazolyl,3-N-ethylhydantoin-1-yl, 3-N-phenylhydantoin-1-yl, or5,5-dimethyl-oxazolidine-2,4-dione-3-yl group.